Regioninfo (#11056)

* advertise a superset of EU regional presets to client devices.

* trunk

docs/lora_region_preset_compatibility_client_spec.md

@@ -153,7 +153,10 @@ These rules are what keep the UX correct across firmware versions. Implement all
 5. **EU region auto-swap caveat.** The firmware treats the EU sibling regions
    (`EU_868` / `EU_866` / `EU_N_868`) specially: if the user is in one of them and selects a
    preset that belongs to a sibling's list, the firmware **swaps the region** rather than
-   rejecting the preset. Consequence for clients: **do not assume the region is immutable
+   rejecting the preset. To make this visible in the picker, the firmware advertises the
+   **same superset** (the union of the trio's presets) for all three sibling regions, so a
+   client filtering per §6 will offer every EU 86x preset regardless of which sibling is
+   currently selected. Consequence for clients: **do not assume the region is immutable
    across a preset change** - after an admin config write, re-read the resulting
    `LoRaConfig` and reflect the (possibly changed) region back into the UI.
 
@@ -249,12 +252,23 @@ so they are stable as listed here:
 | group_index             | default_preset | licensed_only | presets                                                                                                                      |
 | ----------------------- | -------------- | ------------- | ---------------------------------------------------------------------------------------------------------------------------- |
 | 0 (standard)            | `LONG_FAST`    | false         | LONG_FAST, LONG_SLOW, MEDIUM_SLOW, MEDIUM_FAST, SHORT_SLOW, SHORT_FAST, LONG_MODERATE, SHORT_TURBO, LONG_TURBO, MEDIUM_TURBO |
-| 1 (EU 868)              | `LONG_FAST`    | false         | LONG_FAST, LONG_SLOW, MEDIUM_SLOW, MEDIUM_FAST, SHORT_SLOW, SHORT_FAST, LONG_MODERATE                                        |
+| 1 (EU 868)              | `LONG_FAST`    | false         | _EU 86x superset_ (see below)                                                                                                |
-| 2 (EU 866 SRD / "lite") | `LITE_FAST`    | false         | LITE_FAST, LITE_SLOW                                                                                                         |
+| 2 (EU 866 SRD / "lite") | `LITE_FAST`    | false         | _EU 86x superset_ (see below)                                                                                                |
-| 3 (EU 868 narrow)       | `NARROW_SLOW`  | false         | NARROW_FAST, NARROW_SLOW                                                                                                     |
+| 3 (EU 868 narrow)       | `NARROW_SLOW`  | false         | _EU 86x superset_ (see below)                                                                                                |
 | 4 (ham 20 kHz)          | `TINY_FAST`    | **true**      | TINY_FAST, TINY_SLOW                                                                                                         |
 | 5 (ham 100 kHz)         | `NARROW_SLOW`  | **true**      | NARROW_FAST, NARROW_SLOW                                                                                                     |
 
+The **EU 86x superset** advertised by groups 1, 2 and 3 is the union of the trio's own
+band presets, because the firmware auto-swaps region within the trio on preset selection
+(§5), so any of these is a legal pick from any of the three regions:
+
+```text
+LONG_FAST, LONG_SLOW, MEDIUM_SLOW, MEDIUM_FAST, SHORT_SLOW, SHORT_FAST, LONG_MODERATE, LITE_FAST, LITE_SLOW, NARROW_FAST, NARROW_SLOW
+```
+
+The three groups still differ by `default_preset` (`LONG_FAST` / `LITE_FAST` / `NARROW_SLOW`),
+which is why they remain distinct groups despite sharing this preset list.
+
 `region_groups` (region → group_index):
 
 | group | regions                                                                                                                                                       |
@@ -266,9 +280,11 @@ so they are stable as listed here:
 | 4     | ITU1_2M, ITU2_2M, ITU3_2M                                                                                                                                     |
 | 5     | ITU2_125CM                                                                                                                                                    |
 
-> Note groups **3** and **5** carry the same preset list (NARROW\_\*) but are distinct groups
+> Note that several groups can carry overlapping preset lists but remain distinct: groups 1,
-> because they differ in `licensed_only`. Decoders must key on the group, not on the preset
+> 2 and 3 share the EU 86x superset yet differ in `default_preset`, and group **5** (ham
-> list, to preserve the licensing flag.
+> 100 kHz) shares the `NARROW_*` presets with group 3 but differs in `licensed_only`.
+> Decoders must key on the group, not on the preset list, to preserve `default_preset` and
+> the licensing flag.
 >
 > Regions **absent** from the table (no constraint info; see §5.1): `EU_874`, `EU_917`,
 > `ITU1_70CM`, `ITU2_70CM`, `ITU3_70CM`.

src/mesh/RadioInterface.cpp

@@ -55,6 +55,34 @@ static const meshtastic_Config_LoRaConfig_ModemPreset PRESETS_NARROW[] = {PRESET
 
 static const meshtastic_Config_LoRaConfig_ModemPreset PRESETS_TINY[] = {PRESET(TINY_FAST), PRESET(TINY_SLOW), MODEM_PRESET_END};
 
+// The EU_868/EU_866/EU_N_868 trio share the 868 band but own mutually exclusive preset
+// profiles. Selecting a preset locked to a sibling swaps the region to that sibling (see
+// regionSwapForPreset), so from any region in the trio every one of these presets is
+// selectable. This union is what we advertise to clients as the trio's legal list. It is a
+// display-only superset: on-device enforcement still uses each region's own disjoint
+// profile->presets, so this must never be assigned to a RegionProfile (that would make
+// supportsPreset() accept the preset in place and defeat the swap). Keep in sync with the
+// EU_868/EU_866/EU_N_868 profile lists below. Sized to the 11-preset wire cap.
+static const meshtastic_Config_LoRaConfig_ModemPreset PRESETS_EU_SUPERSET[] = {
+    PRESET(LONG_FAST),     PRESET(LONG_SLOW), PRESET(MEDIUM_SLOW), PRESET(MEDIUM_FAST), PRESET(SHORT_SLOW),  PRESET(SHORT_FAST),
+    PRESET(LONG_MODERATE), PRESET(LITE_FAST), PRESET(LITE_SLOW),   PRESET(NARROW_FAST), PRESET(NARROW_SLOW), MODEM_PRESET_END};
+
+// The EU_868/EU_866/EU_N_868 trio own mutually exclusive preset lists. Selecting a preset
+// locked to a sibling means the user wants that sibling region, not the default preset.
+static const meshtastic_Config_LoRaConfig_RegionCode SWAPPABLE_EU_REGIONS[] = {
+    meshtastic_Config_LoRaConfig_RegionCode_EU_868,
+    meshtastic_Config_LoRaConfig_RegionCode_EU_866,
+    meshtastic_Config_LoRaConfig_RegionCode_EU_N_868,
+};
+
+static bool isSwappableEuRegion(meshtastic_Config_LoRaConfig_RegionCode code)
+{
+    for (auto c : SWAPPABLE_EU_REGIONS)
+        if (c == code)
+            return true;
+    return false;
+}
+
 // Region profiles: bundle preset list + regulatory parameters shared across regions
 // presets, spacing, padding, audio, licensed, text throttle, position throttle, telemetry throttle
 const RegionProfile PROFILE_STD = {PRESETS_STD, 0, 0, true, false, 0, 1, 1};
@@ -687,8 +715,13 @@ void getRegionPresetMap(meshtastic_LoRaRegionPresetMap &map)
             grp.default_preset = r->getDefaultPreset();
             grp.licensed_only = r->profile->licensedOnly;
             grp.presets_count = 0;
-            for (size_t i = 0; r->profile->presets[i] != MODEM_PRESET_END && grp.presets_count < maxPresets; i++)
+            // EU 86x siblings advertise the trio's superset - any of those presets is
-                grp.presets[grp.presets_count++] = r->profile->presets[i];
+            // reachable from here via an automatic region swap. Every other region
+            // advertises exactly its own enforced profile list.
+            const meshtastic_Config_LoRaConfig_ModemPreset *advertised =
+                isSwappableEuRegion(r->code) ? PRESETS_EU_SUPERSET : r->profile->presets;
+            for (size_t i = 0; advertised[i] != MODEM_PRESET_END && grp.presets_count < maxPresets; i++)
+                grp.presets[grp.presets_count++] = advertised[i];
         }
 
         // Map this region to its group (capacity checked at the top of the loop).
@@ -963,14 +996,6 @@ static void sendErrorNotification(const char *msg, meshtastic_LogRecord_Level le
     service->sendClientNotification(cn);
 }
 
-// The EU_868/EU_866/EU_N_868 trio own mutually exclusive preset lists. Selecting a preset
-// locked to a sibling means the user wants that sibling region, not the default preset.
-static const meshtastic_Config_LoRaConfig_RegionCode SWAPPABLE_EU_REGIONS[] = {
-    meshtastic_Config_LoRaConfig_RegionCode_EU_868,
-    meshtastic_Config_LoRaConfig_RegionCode_EU_866,
-    meshtastic_Config_LoRaConfig_RegionCode_EU_N_868,
-};
-
 /**
  * If currentRegion is one of the swappable EU regions and preset belongs to a sibling in
  * that trio, return the sibling region that owns the preset. Returns nullptr otherwise.
@@ -978,12 +1003,7 @@ static const meshtastic_Config_LoRaConfig_RegionCode SWAPPABLE_EU_REGIONS[] = {
 const RegionInfo *RadioInterface::regionSwapForPreset(meshtastic_Config_LoRaConfig_RegionCode currentRegion,
                                                       meshtastic_Config_LoRaConfig_ModemPreset preset)
 {
-    bool currentIsSwappable = false;
+    if (!isSwappableEuRegion(currentRegion))
-    for (auto code : SWAPPABLE_EU_REGIONS) {
-        if (code == currentRegion)
-            currentIsSwappable = true;
-    }
-    if (!currentIsSwappable)
         return nullptr;
 
     for (auto code : SWAPPABLE_EU_REGIONS) {

test/test_radio/test_main.cpp

@@ -292,16 +292,30 @@ static void test_regionPresetMap_matchesRegionTable()
         const meshtastic_LoRaPresetGroup &grp = map.groups[gi];
         const RegionInfo *r = getRegion(code);
 
-        // Group's list is non-empty, within the generated array bound, and is the
+        // Group's list is non-empty and within the generated array bound.
-        // region's full list.
         const size_t maxPresets = sizeof(grp.presets) / sizeof(grp.presets[0]);
         TEST_ASSERT_GREATER_THAN_UINT(0, grp.presets_count);
         TEST_ASSERT_LESS_OR_EQUAL_UINT((unsigned)maxPresets, grp.presets_count);
-        TEST_ASSERT_EQUAL_UINT((unsigned)r->getNumPresets(), (unsigned)grp.presets_count);
 
-        // Every advertised preset is legal in this region.
+        // Every advertised preset must be selectable from this region: either legal here,
-        for (pb_size_t p = 0; p < grp.presets_count; p++)
+        // or legal in a sibling the firmware will auto-swap us to (the EU 86x trio, which
-            TEST_ASSERT_TRUE(r->supportsPreset(grp.presets[p]));
+        // advertises the union of the trio's presets rather than just its own).
+        for (pb_size_t p = 0; p < grp.presets_count; p++) {
+            bool selectable =
+                r->supportsPreset(grp.presets[p]) || RadioInterface::regionSwapForPreset(code, grp.presets[p]) != nullptr;
+            TEST_ASSERT_TRUE(selectable);
+        }
+
+        // The region's own enforced presets must all be advertised (advertised is a
+        // superset of the enforced list, never a subset).
+        const meshtastic_Config_LoRaConfig_ModemPreset *enforced = r->getAvailablePresets();
+        for (size_t e = 0; e < r->getNumPresets(); e++) {
+            bool advertised = false;
+            for (pb_size_t p = 0; p < grp.presets_count; p++)
+                if (grp.presets[p] == enforced[e])
+                    advertised = true;
+            TEST_ASSERT_TRUE(advertised);
+        }
 
         // Default preset matches the table, is legal, and is present in the list.
         TEST_ASSERT_EQUAL(r->getDefaultPreset(), grp.default_preset);